<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I am not expert in this but i can suggest few things try conv_thr=10^-8<br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">and use ion/cell_dynamics=bfgs. Also which direction you want to move the atoms?. I mean cell_dofree?. all the xyz direction?<br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Hope it helps you.<br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Manu<br><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jan 5, 2017 at 12:35 PM, ＷＡＮＧ ＹＵＡＮＱＩＮＧ <span dir="ltr"><<a href="mailto:yuanqing.wang@riken.jp" target="_blank">yuanqing.wang@riken.jp</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Dear QE users,<br>
<br>
I am trying to optimize the crystal structure of K2V8O21. The input file is given below. I tried many different sets (vc-realx and relax. constrained or not), or optimization algorithm (BFGS or damp). However, I cannot get converged result. Can someone give me some suggestions? Thank you very much!<br>
<br>
Best,<br>
<br>
Yuanqing Wang<br>
<br>
postdoctor<br>
RIKEN, Japan<br>
<br>
------One input file-------<br>
&control<br>
calculation='vc-relax',<br>
restart_mode = 'from_scratch',<br>
prefix = 'k2v8o21',<br>
outdir = './',<br>
tprnfor = .TRUE.<br>
pseudo_dir = '/pseudo/',<br>
nstep=200<br>
/<br>
&system<br>
ibrav = 0,<br>
nat= 62, ntyp= 3,<br>
ecutwfc = 150,<br>
ecutrho = 600,<br>
tot_charge=0,<br>
occupations='smearing', smearing='mp', degauss=0.03<br>
/<br>
&electrons<br>
mixing_beta = 0.3<br>
/<br>
&ions<br>
ion_dynamics='damp'<br>
/<br>
&CELL<br>
cell_dynamics='damp-pr'<br>
/<br>
ATOMIC_SPECIES<br>
K 39.0983 K.pz-hgh.UPF<br>
V 50.942 V.pz-hgh.UPF<br>
O 15.999 O.pz-hgh.UPF<br>
CELL_PARAMETERS angstrom<br>
13.746484076 0.000000000 -0.193637952<br>
0.000000000 3.360623858 0.000000000<br>
-0.429832895 0.000000000 13.681512366<br>
ATOMIC_POSITIONS angstrom<br>
K 6.984312493 0.000000000 4.188728225 0 0 0<br>
K 6.332338675 0.000000000 9.299146598 0 0 0<br>
K 0.111143470 1.680311929 4.286848404 0 0 0<br>
K 13.205507698 1.680311929 9.201026418 0 0 0<br>
V 10.878749236 1.680311929 12.433287018<br>
V 2.437901942 1.680311929 1.054587499<br>
V 4.008352623 0.000000000 12.539262335<br>
V 9.308298554 0.000000000 0.948612182<br>
V 11.369939010 0.000000000 6.612591821<br>
V 1.946712158 0.000000000 6.875283001<br>
V 4.495045176 1.680311929 6.720753553<br>
V 8.821605991 1.680311929 6.767121270<br>
V 11.150388833 0.000000000 3.743423629<br>
V 2.166262335 0.000000000 9.744451194<br>
V 4.296183684 1.680311929 3.847414705<br>
V 9.020467484 1.680311929 9.640460118<br>
V 12.578611942 0.000000000 1.090039654<br>
V 0.738039229 0.000000000 12.397835067<br>
V 5.704373956 1.680311929 1.184004573<br>
V 7.612277214 1.680311929 12.303870148<br>
O 12.349856377 0.000000000 5.231345609<br>
O 0.966794818 0.000000000 8.256528398<br>
O 5.490033518 1.680311929 5.354972202<br>
O 7.826617675 1.680311929 8.132901806<br>
O 10.708076383 1.680311929 6.225623611<br>
O 2.608574796 1.680311929 7.262250803<br>
O 3.828996973 0.000000000 6.322373797<br>
O 9.487654207 0.000000000 7.165500618<br>
O 12.137386541 1.680311929 0.583012891<br>
O 1.179264646 1.680311929 12.904861320<br>
O 5.265470757 -0.000000000 0.685756586<br>
O 8.051180430 0.000000000 12.802117625<br>
O 11.927069357 1.680311929 11.327461557<br>
O 1.389581812 1.680311929 2.160413266<br>
O 5.060238394 0.000000000 11.437026216<br>
O 8.256412774 0.000000000 2.050848606<br>
O 10.802990364 0.000000000 1.920124897<br>
O 2.513660822 0.000000000 11.567749315<br>
O 3.937601468 1.680311929 2.030377822<br>
O 9.379049718 1.680311929 11.457496389<br>
O 9.720341944 0.000000000 4.289255974<br>
O 3.596309249 0.000000000 9.198618033<br>
O 2.865221165 1.680311929 4.391289428<br>
O 10.451430029 1.680311929 9.096584579<br>
O 1.048281817 0.000000000 5.602802054<br>
O 12.268369056 0.000000000 7.885072366<br>
O 7.933518947 1.680311929 5.487946834<br>
O 5.383132643 1.680311929 7.999927575<br>
O 2.692732203 0.000000000 0.478164303<br>
O 10.623918782 0.000000000 13.009709809<br>
O 9.564010497 1.680311929 0.367862997<br>
O 3.752640694 1.680311929 13.120011112<br>
O -0.030603751 0.000000000 11.047477402<br>
O 13.347255188 0.000000000 2.440397009<br>
O 6.845321995 1.680311929 10.955939637<br>
O 6.471328777 1.680311929 2.531934783<br>
O 4.966539817 0.000000000 3.695467695<br>
O 8.350110955 0.000000000 9.792406726<br>
O 11.803635919 1.680311929 3.578686576<br>
O 1.513015671 1.680311929 9.909187834<br>
O 0.000000000 0.000000000 0.000000000<br>
O 6.873242038 1.680311929 -0.096818975<br>
K_POINTS automatic<br>
1 2 1 1 1 1<br>
<br>
--------output of total force-------------<br>
Total force = 0.051290 Total SCF correction = 0.002130<br>
Total force = 0.051136 Total SCF correction = 0.002608<br>
Total force = 0.050236 Total SCF correction = 0.002396<br>
Total force = 0.049097 Total SCF correction = 0.001622<br>
Total force = 0.047667 Total SCF correction = 0.001084<br>
Total force = 0.046453 Total SCF correction = 0.001397<br>
Total force = 0.044931 Total SCF correction = 0.000588<br>
Total force = 0.043841 Total SCF correction = 0.001269<br>
Total force = 0.042947 Total SCF correction = 0.001489<br>
Total force = 0.042798 Total SCF correction = 0.001499<br>
Total force = 0.043219 Total SCF correction = 0.001842<br>
Total force = 0.043860 Total SCF correction = 0.002046<br>
Total force = 0.045375 Total SCF correction = 0.001577<br>
Total force = 0.046556 Total SCF correction = 0.001423<br>
Total force = 0.047042 Total SCF correction = 0.001028<br>
Total force = 0.047541 Total SCF correction = 0.001137<br>
Total force = 0.046434 Total SCF correction = 0.000862<br>
Total force = 0.046324 Total SCF correction = 0.001308<br>
Total force = 0.046291 Total SCF correction = 0.001539<br>
Total force = 0.046668 Total SCF correction = 0.001693<br>
Total force = 0.047444 Total SCF correction = 0.002223<br>
Total force = 0.047503 Total SCF correction = 0.001856<br>
Total force = 0.047531 Total SCF correction = 0.000283<br>
Total force = 0.047968 Total SCF correction = 0.000493<br>
Total force = 0.048130 Total SCF correction = 0.000548<br>
Total force = 0.048428 Total SCF correction = 0.000401<br>
Total force = 0.049057 Total SCF correction = 0.001568<br>
Total force = 0.049558 Total SCF correction = 0.001533<br>
Total force = 0.050126 Total SCF correction = 0.000547<br>
Total force = 0.051056 Total SCF correction = 0.002082<br>
Total force = 0.051638 Total SCF correction = 0.001535<br>
Total force = 0.052518 Total SCF correction = 0.001070<br>
Total force = 0.053171 Total SCF correction = 0.000721<br>
Total force = 0.053997 Total SCF correction = 0.002044<br>
Total force = 0.055299 Total SCF correction = 0.000850<br>
Total force = 0.057107 Total SCF correction = 0.001969<br>
Total force = 0.058558 Total SCF correction = 0.001402<br>
Total force = 0.060669 Total SCF correction = 0.001204<br>
Total force = 0.063337 Total SCF correction = 0.001733<br>
Total force = 0.065735 Total SCF correction = 0.001408<br>
Total force = 0.068646 Total SCF correction = 0.002278<br>
Total force = 0.071455 Total SCF correction = 0.001691<br>
Total force = 0.074416 Total SCF correction = 0.001644<br>
Total force = 0.077870 Total SCF correction = 0.001039<br>
Total force = 0.082025 Total SCF correction = 0.001121<br>
Total force = 0.086844 Total SCF correction = 0.000942<br>
Total force = 0.092341 Total SCF correction = 0.001927<br>
Total force = 0.098669 Total SCF correction = 0.002091<br>
Total force = 0.114408 Total SCF correction = 0.001387<br>
Total force = 0.114391 Total SCF correction = 0.000697<br>
Total force = 0.124232 Total SCF correction = 0.002167<br>
Total force = 0.136284 Total SCF correction = 0.002503<br>
Total force = 0.150359 Total SCF correction = 0.001559<br>
Total force = 0.166135 Total SCF correction = 0.001821<br>
Total force = 0.184791 Total SCF correction = 0.001960<br>
<br>
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</blockquote></div><br></div>